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Quilt backing, batting & binding calculator

Calculate backing yardage and seams, batting size and binding strips for any quilt size.

Common sizes

Quilt top width (in)

Quilt top length (in)

Backing & batting extra per side (in)

Backing fabric

Binding strip width (in)

Binding fabric usable width (in)

How the numbers are worked out

Backing is the quilt top plus the extra on every side. If that is wider than your fabric, the calculator compares joining panels side by side (vertical seams) with joining them top to bottom (horizontal seams) and recommends the option that uses less fabric.

Binding length is the perimeter plus 12 inches. All yardage is rounded up to the next ⅛ yard so you can buy it straight off the bolt.

How to use it

Enter the finished size of your quilt top, or pick a common size.
Check the extra backing and batting you want on each side. Longarm quilters usually ask for 4 inches per side.
Choose the backing fabric width: standard 42–44 inch quilting cotton or 108 inch wide backing.
Read the yardage for backing, binding and batting. The backing result shows whether to seam it vertically or horizontally.

Questions

How much bigger should quilt backing be than the top?

At least 4 inches larger on every side (8 inches in total each way) if a longarm quilter is quilting it, and 2–3 inches per side if you quilt it yourself.

How do I calculate binding?

Add the four sides of the quilt plus about 12 inches for joining and mitred corners. Divide by the usable width of your fabric (about 40 inches) to get the number of strips, then multiply by the strip width, usually 2.25 or 2.5 inches.

What size batting do I need?

The same size as your backing: the quilt top plus your overhang on each side. Pre-packaged batting comes in standard sizes; the calculator suggests the smallest that fits.

Why is the usable fabric width 40 inches?

Quilting cotton is sold 42–44 inches wide, but after removing the selvages and allowing for shrinkage about 40 inches is reliably usable.